diff --git a/src/pack_unpack.c b/src/pack_unpack.c
index 76d946b..af381a5 100644
--- a/src/pack_unpack.c
+++ b/src/pack_unpack.c
@@ -350,6 +350,7 @@ static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
 {
     int ret = -1;
     int strict = 0;
+    int gotopt = 0;
 
     /* Use a set (emulated by a hashtable) to check that all object
        keys are accessed. Checking that the correct number of keys
@@ -406,7 +407,7 @@ static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
         next_token(s);
 
         if(token(s) == '?') {
-            opt = 1;
+            opt = gotopt = 1;
             next_token(s);
         }
 
@@ -432,10 +433,26 @@ static int unpack_object(scanner_t *s, json_t *root, va_list *ap)
     if(strict == 0 && (s->flags & JSON_STRICT))
         strict = 1;
 
-    if(root && strict == 1 && key_set.size != json_object_size(root)) {
-        long diff = (long)json_object_size(root) - (long)key_set.size;
-        set_error(s, "<validation>", "%li object item(s) left unpacked", diff);
-        goto out;
+    if(root && strict == 1) {
+        /* We need to check that all non optional items have been parsed */
+        const char *key;
+        json_t *value;
+        long unpacked = 0;
+        if (gotopt) {
+            /* We have optional keys, we need to iter on each key */
+            json_object_foreach(root, key, value) {
+                if(!hashtable_get(&key_set, key)) {
+                    unpacked++;
+                }
+            }
+        } else {
+            /* No optional keys, we can just compare the number of items */
+            unpacked = (long)json_object_size(root) - (long)key_set.size;
+        }
+        if (unpacked) {
+            set_error(s, "<validation>", "%li object item(s) left unpacked", unpacked);
+            goto out;
+        }
     }
 
     ret = 0;
diff --git a/test/suites/api/test_unpack.c b/test/suites/api/test_unpack.c
index fac1be3..6b76106 100644
--- a/test/suites/api/test_unpack.c
+++ b/test/suites/api/test_unpack.c
@@ -378,4 +378,23 @@ static void run_tests()
     if(i1 != 42)
         fail("json_unpack failed to unpack");
     json_decref(j);
+
+    /* Combine ? and ! */
+    j = json_pack("{si}", "foo", 42);
+    i1 = i2 = 0;
+    if(json_unpack(j, "{sis?i!}", "foo", &i1, "bar", &i2))
+        fail("json_unpack failed for optional values with strict mode");
+    if(i1 != 42)
+        fail("json_unpack failed to unpack");
+    if(i2 != 0)
+        fail("json_unpack failed to unpack");
+    json_decref(j);
+
+    /* But don't compensate a missing key with an optional one. */
+    j = json_pack("{sisi}", "foo", 42, "baz", 43);
+    i1 = i2 = i3 = 0;
+    if(!json_unpack_ex(j, &error, 0, "{sis?i!}", "foo", &i1, "bar", &i2))
+        fail("json_unpack failed for optional values with strict mode and compensation");
+    check_error("1 object item(s) left unpacked", "<validation>", 1, 8, 8);
+    json_decref(j);
 }